Dr Williams’ tenure included Benedict XVI’s historic visit to the UK and last month he was invited by the Pope to address leading Catholic clergy from around the world in Rome.

But Dr Williams recently acknowledged that the impending vote to ordain women as bishops effectively ruled out anything resembling a merger.

Writing on behalf of the Pope, the Cardinal said: “Relations between the Roman Catholic Church and the Anglican Communion are a hugely important part of the ecumenical call for all Christians to seek greater fidelity to the Lord’s will, so clearly expressed in his prayer to the Father at the Last Supper 'that all may be one'.

“For almost 50 years, as you are well aware, there has been a formal theological dialogue which continues to seek a deeper understanding of the great heritage shared by Anglicans and Catholics, as well as the points of divergence which still impede fully restored ecclesial communion.

“During that same time, relations between succeeding Popes and Archbishops of Canterbury have been marked by numerous meetings which have expressed intense spiritual and human friendship, and a shared concern for our gospel witness and service to the human family.

"I am certain that under your leadership those excellent relations will continue to bear fruit, and I look forward to meeting you personally, and to future opportunities to share our common commitment to the cause of Christian Unity, 'so that the world may believe'.”